Many indexable cutting inserts used for turning, milling or other metal cutting operations include one or more operative and/or non-operative surfaces having non-planar shapes, for example, having concave, convex, bent, sunken, undulating, or bowed shapes, or other different non-planar shapes. These surfaces assume their non-planar shapes, for example, in order to satisfy various constraints arising from functional and geometrical requirements involved in the design of the cutting insert.
Some indexable, double-sided cutting inserts, for example, have two opposing surfaces, for example, two opposing side surfaces that assume identical, non-planar shapes. When such a cutting insert is retained in an insert pocket of a cutting tool, a first of the two opposing side surfaces functions, for example, as a clearance surface, and the second, opposite side surface may function as an engagement surface of the cutting insert, e.g., by engaging a supporting wall of the insert pocket. When the insert is indexed, for example, the two opposing side surfaces interchange positions and thus assume one another's functionality.
However, e.g., referring to the above example, due to ordinary imperfections in the manufacture of the cutting insert, in some instances the clearance surface is provided with beneficial clearance properties, but at the same time the engagement surface provides only deteriorated engagement with the supporting wall of the insert pocket. In attempt to overcome this, individual and extensive grinding of a plurality of surfaces and edges of each cutting insert has to be performed. The extensive grinding may be expensive, and in addition, in some instances the extensive grinding in combination with the geometry of the cutting inserts may result in unnecessary and even undesired grinding of cutting edges of these cutting inserts, for example, during grinding of other portions thereof.
It is the object of the present invention to provide a cutting insert and a cutting tool therefor, which significantly reduce or overcome the aforementioned disadvantages.